Protecting the Environment - Developing Green Packaging Materials (2)

2. Polylactic acid packaging material

Polylactic acid has become a research and development hotspot worldwide. It is a new type of biodegradable polymer material polymerized by many lactic acid molecules and can be completely decomposed into water and carbon dioxide without any harm to the environment.

In November 2004, the degradable polylactic acid material developed by Shanghai Xinli Industrial Microbial Technology Co., Ltd. and the School of Materials Science and Engineering of Tongji University has been successfully developed and has been listed as a major industrialization project in Shanghai City for Science and Education.

Countries such as the United States, France, and Japan have developed and produced lactic acid from raw materials such as corn, sugar cane, sugar beets, potatoes, and other agricultural and sideline products to produce polylactic acid. The process used by US LLC to make biodegradable plastics from corn is as follows: First, the corn is ground into powder, the starch is separated, and the original glucose is extracted from the starch. Then anaerobic fermentation of Lactobacillus, the fermentation process with liquid caustic soda to generate lactic acid, fermentation broth after purification, using electrodialysis process, made up to 99.5% purity of L-lactic acid. The extracted lactic acid is then made into the final polymer-polylactic acid. The annual global output of 600 million tons of corn makes it the raw material of choice for biodegradable plastics.

The United States CollegeFarm brand candy packaging uses a biodegradable resin polylactic acid film. This film has crystal transparency and excellent kink retention, printability and strength, and is highly barrier to better preserve the aroma of the candy. A German company successfully developed a green food cup with rapid natural decomposition using polylactic acid as a raw material, which has opened up a practical new way to solve the problem of degradation of disposable plastic packaging.

3 natural biological packaging materials

Natural biological packaging materials such as wood, bamboo materials, sawdust, hemp cotton, wicker, reeds, straw, wheat straw, etc., can be easily decomposed in the natural environment, do not pollute the ecological environment, and the resources are renewable and the cost is low. If the bamboo packaging products can be used for the second time, the waste can be burned and utilized; the compost can be used as fertilizer; the waste can be naturally degraded. Bamboo-engraved plywood is an excellent green packaging material because of its high strength, low price, light weight, easy recycling of waste, and no environmental pollution.

4. Food waste green packaging

According to the New Scientist magazine, biochemists at the Hawaii Institute of Natural Energy have made food waste a biodegradable polymer that researchers have humorously called "perfect plastic." This type of plastic, which can be degraded in a short time, is widely used not only for making packages such as bottles and bags but also for making capsules for medicines. According to the biochemist of the Institute of Natural Energy, the raw material of the new biodegradable plastic is a mixture of water and various food wastes, and 22 to 25 kg of biodegradable plastic can be produced per 100 kg of mixture, which greatly reduces the production cost.

Third, measures to promote the development of green packaging materials

1. Formulate a green packaging material development plan

The development of green packaging materials involves many high-tech, industrial developed countries have been researching fully biodegradable plastics for several years, but so far there are not many real industrial products, which involves many experimental research and industrial production problems. The development of green packaging materials requires the cooperation of industrial enterprises, research institutes, and universities. Therefore, it is necessary to formulate a five to ten-year development plan for green packaging materials, and put forward major research and development projects and goals, such as high-performance, low-cost pulp molded disposable tableware and packaging products, and honeycomb box instead of wooden box packaging. Production equipment, plant fiber cushioning packaging products, fully biodegradable plastics, edible packaging materials, high-strength thin-walled lightweight glass bottles, high-quality recycling and recycling technology of waste packaging, especially high-quality recycling technology of waste plastics, waste The green plastic technology of the company concentrates on people's property, organizes elite teams, and cooperates with plans and targets in order to make the development of green packaging materials in China the forefront of the world.

2. Formulate and improve the legal system of green packaging

In the past decade or so, developed countries have taken measures one after another and have formulated various laws and directives, mainly in the following categories.

One is to prohibit the use of certain packaging materials in legislation. For example, legislation prohibits the use of packaging materials containing components such as lead, mercury, and copper; appliances that cannot be reused; packaging materials that achieve a specific recycling ratio.

The second is to establish a storage return system. Many countries require that alcoholic beverages and soft drinks should use reusable containers. Some countries (such as Denmark) require that they fail to meet this standard and refuse to import it.

The third is the implementation of tax incentives or fines. That is, manufacturers who manufacture and use packaging materials are encouraged to provide tax exemption, low tax concessions, or impose higher taxes based on the safety of the raw materials or packaging they use for packaging, or the use of partially recycled packaging materials. Use renewable resources.

The fourth is to promote proper packaging. Excessive packaging causes waste of resources and also causes unnecessary environmental pollution. Some developed countries are advocating proper packaging and have introduced some regulations in succession. For example, in the United States, the degree of complexity of product packaging has been regulated in a certain proportion. If excessive packaging exceeds the requirements, heavy penalties are imposed. This forces manufacturers to simplify packaging. Japan even proposes zero packaging.

Although China does not have a green packaging law, it does not mean that there are no laws and regulations that regulate green packaging. The “Environmental Protection Law” defines the principle of harmonization of environmental protection with economic and social development; the principle of prevention, prevention and control, and comprehensive governance; polluter pays, user compensation, developer protection, the principle of destroyer recovery, and The principle of the masses to protect the environment. In addition, the "Environmental Protection Law" also stipulates the basic systems of the environmental impact assessment system, the "three simultaneous" system, the pollutant discharge system, the permit system, and the deadline governance system. Legislation management, as a compulsory measure in environmental management, is an effective measure adopted by all countries in the world. To protect the smooth operation of the green packaging system, a sound and complete legal system must be established, and the production of packaging must be managed through legislation. Circulation and use, with laws and regulations to promote the development of green packaging.

3. Research and development of environmentally friendly production and recycling technology

The environmental performance of packaging materials should be evaluated throughout the life cycle. In fact, the environmental pollution caused by paper, plastics, metal, and glass packaging used mainly in the production process is far greater than the environmental pollution caused by waste disposal. For example, waste paper discharged from paper packaging in pulp and paper, and plastic packaging in petroleum raw materials. Pollution caused by atmospheric pollution in the refining process, noise and smoke generated by metal packaging in the grinding process, coating process, and body and mind pollution caused by smoke, dust and carbon dioxide emitted by glass packaging in the melting process, and silicon dioxide are brought to the environment The pollution that comes... is very serious. Therefore, in order to make the packaging material have "green" performance throughout its life cycle, clean production must be carried out. Among the three elements of "clean energy and raw materials," "clean production processes," and "clean products," the most important is the development of clean production technology. Clean production processes are "less waste" and "non-waste" processes. In order to establish closed loops, to volatilize or precipitate or run off the material lost in the production process, through recycling, reuse as raw materials, and establish a closed production process from raw material input to recycling of wastes. Reducing the amount of wastes discharged from the outside world will not only increase the utilization rate of resources, but also radically eliminate the “three wastes” and prevent the packaging industry from causing harm to the environment. China has formally implemented the "Cleaner Production Promotion Law" from January 1, 2003. Enterprises that are toxic and harmful to the production process and pollute the environment must be subject to compulsory cleaner production audits. Therefore, it is very important for the development of green packaging materials to vigorously develop clean production process technologies for green packaging materials.

Packaging made from a single material is easy to recycle, and composites with multiple layers must consider whether it is easy to separate and not hinder reuse. If the aluminum beverage is heard and the surface is coated with an organic coating, the organic coating can be burned during recovery melting without causing difficulty in recycling, and the composite paper-plastic packaging is difficult to separate for purification. The big advantage of composite materials is that they have multiple functions. The biggest drawback is that they are difficult to recycle, difficult to separate and separate, and if the composite materials are mixed into a single material during recycling, the quality of the recovery of a single material will be damaged, such as aluminum paper and plastic. Composite materials mixed into a single cardboard recycling material, will destroy its beating performance; mixed into a single plastic film, will also make recycled recycled products scrapped. Therefore, when the composite material is recycled, it can only be used as a fuel, and it is burned in the incinerator to recover heat energy. At present, to resolve the contradiction between the high-functionality and environmental performance of composite materials, the main directions are: 1 to develop a single high-performance material to replace composite materials; 2 to develop green composite materials that are easy to recycle. Both are difficult to develop.

The green packaging of commodities is an irreversible development trend, and it is also a complex system engineering. The use of green packaging materials and effective recycling are two important links. Only the development and application of packaging materials and the recycling of recycling materials are simultaneously developed. Only in order to achieve a true green cycle.

Source: China Packaging Industry